Telephone receiver



Feb 5, 1924;

G. M. STRATTQN TELEPHONE RECEIVER Filed Sept.- 12. 1922 Watented Feb. 5, T9.

enoaen eraa'rroia, or SALT LIE crrr, urea.

TELEPHONE RESET." 2:.

Application filed September 12, 1922. Serial No. 587,701.

To all whom it may concem:

. Be it known that T, GEoRonM. Srmrron,

a citizen of the United States, residing at Salt Lake City, in the county of Salt Lake a and State of Utah, have invented a certain new and useful Improvement in Telephone Receivers, of which the following is a sp'ec1 fication.

My invention relates to telephone receiv- 1o ers and the like, and the object of the invention is to amplify the eflect of the coil upon the diaphragm. I obtain this object by the mechanism illustrated in the accompanyin drawings, in which 15 Tigure 1 is a sectional view, partly in diametral section, of the complete device and Flgure 2 is a top plan v1ew of the parts shown in Figure 1, the housing being removed to reveal the parts within.

. Like numerals denote like parts in the two views.

In the form selected to illustrate the invention the receiver has a housing 1 onto which screws a cap or car piece 2 in the usual manner. This cap forms a clamp for holding the diaphragm 3' in place, and has a central aperture 4 through which the air waves are emitted. A cup 5 is also clamped in place by cap 2. The parts thus far described are known and may be considerably varied without exceeding the scope of the invention.

Mounted upon the back of the cup 5 and enclosed within the housing are two perma nent magnets 6, 8. For the major part they are cylindrical and superposed. The ends, however, overlap to a certain extent although they are spaced from each other as best illustrated in Figure 1. Between one pole of the upper magnet and the other pole 12 thereof is placed an armature 14 fastened to a core 15 of an electromagnet havin a coil 16 arranged between insulating en l discs or flanges 18. A secondarmature 2O lies between the upper pole 22 of magnet 8 and the lower'pole 24thereof. This second armature is also secured to the core 15 and hence the two armatures and the core always operate in unison. The poles as well as the cup 5 are suitably apertured to accommodate the said core 15 and the armatures may said poles.

The core extends up through a spring 26 and is suspended by a nut 25 which rests upon said spring. In the case illustrated thisspring is of special design, being approximately of spiral shape and having a foot 28 mounted upon the fiat upper pole 10 of the permanent magnet 6. Said foot is rigidly secured to the pole by rivets 80 or otherwise. The result of this construction is that while the spring is resilient and will yield in a direction perpendicular to the plane of the spiral and lengthwise of core 15, it will hold the core rigidly centered with respect to the coil 16.

.Gore 15 also extends downward through be regarded as floating between the cup 5 and through the diaphragm 3 where it carries a washer 32 which makes surface contact with the diaphragm. The spring 26 is biased upward (Figure 1) and, acting through the core 15 and washer 32,

exerts a moderate upward pressure on the diaphragm. In other words, the core is constantly under tension due to the action of the spring and exerts a moderate upward or inward pressure upon the diaphragm.

The coil 16 previously mentioned is in series in the line conductors (not shown) in a manner thatwill be readily understood by those familiar with the art.

- Operation: When current is flowing in coil 16 it will induce opposite polarities in the armatures 14: and 20. For example, the upper armature l-i (Fi re 1) will be north and the lower one sout The poles of the permanent magnet are so arranged as to augment each other in their action upon the armatures. For example, the upper and lower poles 10 and 24: will be north and the intermediate pole pieces 12 and 22 will be south. The force of the spring 26 and the diaphragm 3 and the combined forces of the poles of the permanent magnets will come to a state of equilibrium for any given strength of current in the coil 16 and hence will remain motionless so long as there are no variations in the current conditions in the coil. If, now, electrical fluctuations or pulsations occur in the coil, correspondingly magnetic fluctuations will be induced I claim as new and desire to secure by Letters Patent is':

1. In a receiver for telephones and the like, a diaphragm, an electro magnetic coil having a movable core connected to the diaphragm for operating it, armatures secured to the core at opposite ends of the coil, and magnets having poles of opposite polarity on opposite sides of the armatures.

2. In a receiver for telephones and the like, a diaphragm, an electro magnetic coil having a movable core, armatures secured to the core at opposite ends of the coil, magnets having poles of opposite polarity on opposite sides of the armatures, and means for yieldingly holding the core in engagement With the diaphragm.

3. In a receiver for telephones and thelike, a diaphragm,'an electro magnetic coil having a movable core, an armature secured to the core at each end of the coil but spaced from the coil, the core being adapted at one end to engage the diaphragm for operating it, a spring operative upon said core to hold it in yielding contact with the diaphragm, and two permanent magnets, each having poles of'opposite polarity lying on either side of the armat-ures, and spaced from said armatures whereby the armatures float between said poles.

a. In a receiver for telephones and the like, a diaphragm, an electro magnetic coil having a movable core connected to the diaphragm for operating it, armatures secured to the core at opposite ends of the coil, permanent magnets having poles of opposite polarity on opposite sides of the armature, and means for yieldingly holding the core in contact with the diaphragm, like poles of the permanent magnets lying nearest to the ends of the coil. 1

5. In a receiter for telephones and the like, a diaphragm, an electro magnetic coil having a movable core, armatures secured to the core at opposite ends of the coil, permanent magnets having poles of opposite polarity on opposite sides of the armatures, and spaced from the armatures, and a spring for yieldingly holding the core in engagement with the diaphragm, the spring being formed of approximately flat metal arranged approximately in the form of a spiral, one end of the spiral being stationary and the other being connected to the core.

In Witness whereof, I have hereunto subscribed my name.

GEORGE M. STRATTON. 

